August 31, 2012
Xinguang Chen, M.D., Ph.D.
Xinguang Chen, M.D., Ph.D., professor of Pediatrics in the WSU School of Medicine, and Feng Lin, Ph.D., professor of Electrical and Computer Engineering in the College of Engineering, have found a way to provide policymakers with hard evidence.
Most adult smokers in the United States report trying their first cigarette before age 18, according to government statistics, with more than 80 percent of established smokers starting before high school graduation. Earlier initiation has been associated with greater smoking frequency and number of cigarettes smoked per day.
Only about 5 percent of established smokers ever quit completely, Dr. Chen said, making prevention in adolescence a critical and strategic priority for tobacco control.
“The number of smokers year to year at any given time is an accumulation of past experience,” he said. “Our methodology has the power to glean that information from one cross-sectional survey, overcoming the limit to track people over time.”
School-, community- and family-based prevention programs have been effective, he said, but evaluating their success at the national level has been a challenge because of the high cost associated with longitudinal data collection and blank groups for comparison.
“We get so much national survey data every year, but we cannot see the real impact of these programs, or get a feeling for the accumulation and meaning of smoking prevention knowledge they pass along,” Dr. Chen said.
In “Exposure to School and Community Based Prevention Programs and Reductions in Cigarette Smoking Among Adolescents in the United States 2000-08,” supported by funding from the National Institute on Drug Abuse of the National Institutes of Health (grant No. R01 DA022730) and published recently in the journal Evaluation and Program Planning, Drs. Chen and Lin describe a methodology and an analytical approach capable of extracting longitudinal information from cross-sectional survey data. Based on a probabilistic discrete event system, the method requires just one wave of data to assess behavior progression. It treats individuals in multi-year cross-sectional surveys as a series of snapshots of a stable system, overcoming the challenges to previous methods.
The research team examined data on children and teens ages 12 to 17 from the National Survey on Drug Use and Health. They found that fewer of those exposed to prevention programs started smoking, more of them quit if they did start and fewer ex-smokers resumed the habit.
WSU researchers also found that state funding cuts in smoking prevention programs from 2003 to 2005 affected those numbers adversely, Dr. Chen said, possibly because less money meant fewer new school and community personnel were trained in how to conduct smoking prevention programs.
Researchers noted a time lag of one to two years between the funding cuts and behavior reversals.
The latter point takes on renewed importance with the beginning of an economic recovery, Dr. Chen said.
Because state spending on prevention has increased slowly since the time of the cuts, he expects smoking startup, quit and relapse numbers to reverse course.
Dr. Chen realizes that policymakers have a number of health-related issues to consider in the funding allocation process, but he said that given the demonstrated, widespread ill effects of smoking on rates of cancer and heart disease, smoking prevention should remain at the top of the priority list because of the health care costs that can be avoided.
“It’s an investment,” he said. “Given the financial difficulties the nation is facing, policymakers should consider the potentially powerful impact offered by relatively low-cost nationwide substance use prevention campaigns.”